The Forecast in the Streets

The physical impacts of the global warming forecast can be bracketed with some degree of statistical confidence. Biological effects are more difficult to gauge, except in special cases such as the likely demise of polar bears that would result from the demise of Arctic sea ice. The societal effects, however, are nearly uncharted territory, at least to me. Perhaps the topic of global warming suffers from the same sort of cultural divide as university faculties, between the techies and the touchies; that is the sciences and the humanities. A new report (pdf) called The Age of Consequences, just released by the Center for Strategic and International Studies and the Center for a New American Security, tries to bring the social sciences, in particular history, geography, and political science, into the forecast of climate change in the coming century. It makes for fascinating if frightening reading.

The report was based on discussions of a group of senior luminaries with a wide range of expertise. I already knew or knew of and respect the climate scientists Mike MacCracken and Bob Correll, and Ralph Cicerone, head of the National Academy of Sciences. The group also included Nobel laureate Thomas Schelling, former CIA Director James Woolsey, former Chief of Staff to the President John Podesta, and former National Security Advisor to the Vice President Leon Fuerth. (Apparently not all group members, listed in the executive summary on page 8, got writing assignments, so not all of them are listed as authors.)

Images of the future can be constructed based on the lessons of history. The history chapter (beginning on page 26) begins with Table 1, which I will reprint here:

Event

Potential deaths

Volcanic eruptions

104

Earthquakes

105

Floods

106

Droughts

107

Epidemics

108

It is sobering to note that the potential horsemen of climate change, floods, droughts, and epidemics, are all at the big end of this list. There is no historical precedent for the type of global multidimensional challenge that changing climate may bring, but there are common elements in societal responses to natural disasters, and many of the impacts of climate change will be regional in scope rather than global, like natural disasters.

The report considers the historical societal impacts of disasters ranging from bubonic plagues in the middle ages to Katrina. History teaches that people tend to return to religion in times of trouble, and to turn against people outside their social group. Governments are destabilized by hard times. Natural disasters tend to impact most strongly in less affluent parts of the world.

History also teaches that people have a tendency to develop ways of coping with environmental fragility, by choices of individual living strategies such as the ability to migrate, or by decisions made at the societal level, such as engineered flood control measures or mobilizing assistance from outside. The report offers the idea that it takes a population a few generations to learn how to operate within the limits of its natural world. For example, the report attributes the dust bowl drought in some measure to environmental inexperience of a population who had only recently migrated from more humid regions. With our recent increased mobility, and with climate change itself, we find ourselves losing this buffer of experience and understanding.

The group imagined three potential scenarios, labeled expected, severe, and catastrophic. These are not forecasts exactly, since forecasting society is even harder than forecasting climate, which is itself pretty dicey on a regional spatial scale, but rather a fleshing out of plausible possibilities, a story-telling, visualization-type exercise.